Carburetor



.Aug. 7, 1956 R. w. SUTTON ETAL CARBURETOR 2 Sheets-Sheet 1 Filed Oct. 50, 1953 I N 0 mm 0 Wm B A/VC/J 15: 561/77 BY 1956 R. w. SUTTON EI'AL 2,757,913

' CARBURETOR Filed Oct. 30, 1955 v 2 Sheefs-Sheet 2 .94 3 I 'l V I I'I-IIIIII lg a United States Patent CARBURETOR Robert W. Sutton and Francis E. Scutt, Elmira, N. Y., assignors to Bendix Aviation Corporation, Sleuth Bend, Earth, a corporation of Delaware Application October 30, 1953, Serial No. 389,229

2 Claims. (Cl. 261-23) This invention relates to carburetors for internal combustion engines, and more particularly to an economizer mechanism to enable the carburetor to supply fuel to the engine in increased quantity to increase the power thereof when needed.

Most carburetors as now constructed include a device, usually referred to as an economizer or power jet, which includes a valve controlled by a piston or diaphragm subjected to the vacuum in the intake manifold to increase the rate of fuel supplied to the carburetor, and thereby enrich the fuel air mixture, when the throttle is in or near its fully opened position. In carburetors of the tyep having a plurality of mixture chambers, each having a main metering system, a single device has been provided for controlling the common fuel inlet to a plurality of intercommunicating power enrichment passages each of which connect with a separate main metering system.

Power enrichment devices of this type have been unsatisfactory in permitting pressure pulsations in the fuel to cause a surging of fuel through the intercommunicating passages of the device, whereby the flow of fuel to the mixture chambers is uneven or unequal. Pressure pulsations may appear in the fuel as a result of air being bled therein to form an emulsion or they may appear as a result of dissimilar or uneven operation of the separate mixture chambers, viz. one chamber may be operating on the idling system while the other operates on the main system or the chambers may be operating in a critical range where the discharge fluctuates between idle and main discharge system. Whatever the cause of the pressure pulsations, the resultant surging of fuel through the intercommunicating passages of power enrichment device may result in a change of the fuel-air mixture when it is not desired thereby resulting in a loss of gasoline econo my and poor engine performance.

It is therefore a principal object of the present invention to provide an economizer or power enrichment device for a carburetor in which the surging of fuel there through is prevented.

Another object of the invention is to provide an enrichment device for a carburetor having a plurality of mixture chambers wherein the inter-communication of said chambers through said device is controlled.

A further object of the invention is to provide an economizer device for a carburetor having a plurality of fuel discharge ports which may be easily assembled and adjusted to insure an even and equal flow of fuel to said ports.

Further objects and advantages will be apparent from the following description taken in connection with the appended drawings in which:

Figure 1 is a top plan view partially in section of a carburetor embodying my invention;

Figure 2 is a vertical cross-sectional view taken along the line 2-2 of Figure 1;

Figure 3 is a vertical cross-sectional view taken along the line 33 of Figure 1;

2,757,913 Patented Aug. 7, 1956 Figure 4 is an enlarged, fragmentary cross-sectional view of the valve insert shown in Figure 2; and

Figure 5 is an enlarged, fragmentary view of the power enrichment well shown in Figure 1.

Referring more specifically to the drawings numeral 10 designates the main body of a downdraft carburetor having a pair of mixture chambers 12 and 14, 16 and 18 large venturis for each chamber and 20 and 22 small venturis located in each of said large venturis. Numeral 24 designates a throttle body, 26 and 28 throttle valves for each of said chambers, 30 an air horn in which is mounted a choke valve 32 on a shaft 34. The shaft is offset from the center of the induction passage to unbalance the choke valve so that air flow through the induction passage will tend to open the valve. A fuel bowl 36 contains floats 38 for regulating the fuel supply to a main metering system which includes main discharge jets 42 and 44, which extend from a point near the bottom of the fuel bowl to the throat of the small venturis 20 and 22, respectively, main metering restrictions 46 and 48, and a plurality of air inlet orfices designated 50 and 52 through which air from bleeds 54 and 56 is admitted.

A power enrichment device 60 including a seat member insert 62 having an inlet 63, a valve 64 in said member urged toward closed position by a spring 66, communicates with main discharge jets 42 and 44 posterior to metering restrictions 46 and 48 through passages 68 and 70, respectively.

A well located in the main body casting 10 opens into the fuel bowl 30 and contains a pair of opposed, arcuate chambers 84 and 86 located in the side wall of said well near the upper end thereof. A portion of the main body casting circumferentially separates said chambers 84 and 86 from each other. Passages 68 and 70 are in communication with chambers 84 and 86 through restrictions 88 and 90 respectively. The lower end of well 80 is threaded to receive the externally threaded seat member 62 in which a plurality of ports 87 are so arranged that at least one port will register with each of chambers 84 and 86. Ports 87 provide the sole means of communication between chambers 84 and 86 and are controlled by a cylindrical or ring-shaped raised portion 92 on the valve 64. A conical shaped portion 94 on valve 64 is adapated to seat in the inlet 63 simultaneously with the closing of ports 87 by the portion 92. A stem 96 formed on the conical end of said valve protrudes from the inlet when the valve is closed and is adapted for engagement by rod 97 connected to piston 98 slidably disposed in a cylinder 99. The rod 97 is urged towards its extended or valve opening position by a spring 100 and is urged toward and held in its retracted position by manifold vacuum transmitted through conduit 102 which connects the upper end of the cylinder with the induction passage on the engine side of the throttle.

The carburetor contains in addition to those elements mentioned, an automatic choke control device, an idle system and accelerating pump usually found in conventional float type automotive carburetors. A description of these elements here is not necessary since their construction is .well known.

In the operation of the device, after the engine has begun to fire, manifold vacuum transmitted through conduit 102 moves rod 97 to its retracted position and compresses spring 100. Valve 64 is urged towards closed position by spring 66 successively closing ports 87 and inlet 63 and thereby cutting olf or interrupting communication between passages 68 and 70 and thus preventing surging of fuel between the main discharge jets. When the manifold vacuum has dropped to some predetermined value, spring 100 takes over to move rod 97 into engagement *with stem 96 'opening valve 64 and establishing communication between the inlet 63 and passages 68 and 70 through ports 87 and chambers 84 and 86, whereby "an increased amount .of fuel is supplied to the jets 42 and 44 to enrich the fuel-air mixture delivered to the engine.

Other modifications and arrangements may be made without departing *from the scope of the invention.

1 claim:

l. A ,po wer enrichment device fora carburetor having a plurality of induction passages and a fuel bowl comprising a well, a pair 'o'f opposed arcuate chambers in the side wall of said well, a conduit connecting each of said chambers with an induction passage, a valve seat member in said well, ,a plurality of ports .in said member located so that at least one port will register with each of said chambers, an inlet in said member in communication with said fuel bowl, and a valve reciprocably mounted in said memberadapted in one position to close said ports and prevent communication between said conduits.

2. A power enrichment device for a carburetor having at least two induction passages and a fuel bowl, comprising a well, a pair of chambers in the side wall of said well, a conduit adapted to connect each of said chambers with an induction passage, a valve seat member in said well, a pair of ports in said member, each of said ports being adapted for registration with a chamber, an inlet in said member in communication with said fuel bowl, and a valve reciprocably mounted in said member adapted in one position to close said inlet .and said ports .to prevent communication between said conduits.

References Cited in the file of this patent UNITED STATES PATENTS 931,532 Wainwright Aug. 17, 1909 1,747,598 Popp Feb. 18, 1930 2,296,697 Ball Sept. 22, 1942 2,345,168 Wirth et al Mar. 28, 1944 2,464,328 Mallory Mar. 15, 1949 2,642,082 Anderson et a1. June 16, 1953 

